Use JDK 11 for build workflow (#4250)

.github/workflows/build.yml

@@ -34,10 +34,10 @@ jobs:
       - name: Clone repo
         uses: actions/checkout@v2
 
-      - name: Set up JDK 1.8
+      - name: Set up JDK 11
         uses: actions/setup-java@v1
         with:
-          java-version: 1.8
+          java-version: 11
 
       - name: Copy CI gradle.properties
         run: |